20426221 has 4 divisors (see below), whose sum is σ = 20440444. Its totient is φ = 20412000.

The previous prime is 20426209. The next prime is 20426233. The reversal of 20426221 is 12262402.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (20426209) and next prime (20426233).

It can be written as a sum of positive squares in 2 ways, for example, as 11492100 + 8934121 = 3390^2 + 2989^2 .

It is a cyclic number.

It is not a de Polignac number, because 20426221 - 2⁹ = 20425709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20426201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4680 + ... + 7921.

It is an arithmetic number, because the mean of its divisors is an integer number (5110111).

Almost surely, 2^20426221 is an apocalyptic number.

It is an amenable number.

20426221 is a deficient number, since it is larger than the sum of its proper divisors (14223).

20426221 is a wasteful number, since it uses less digits than its factorization.

20426221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14222.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 20426221 is about 4519.5376975970. The cubic root of 20426221 is about 273.3564603011.

Adding to 20426221 its reverse (12262402), we get a palindrome (32688623).

The spelling of 20426221 in words is "twenty million, four hundred twenty-six thousand, two hundred twenty-one".